Morphometric study of the aortic and great pulmonary arterial pathways in human foetuses.

In prenatal and pediatric cardiovascular surgery knowledge of luminal diameters of the aortic and great pulmonary pathways is essential. The internal diameters of the aortic and great pulmonary pathways in 131 human foetuses (65 male, 66 female) were studied by means of anatomical, digital and statistical methods. During foetal development the absolute diameters revealed a linear increase. Correlation coefficients between these diameters and foetal age were statistically significant (P< or =0.05) for each age group and reached following values: r1 = 0.70 for the aortic bulb, r2 = 0.79 for the ascending aorta, r3 = 0.77 for the aortic isthmus, r4 = 0.79 for the descending aorta, r5 = 0.63 for the pulmonary trunk, r6 = 0.36 for the arterial duct, r7 = 0.46 for the right pulmonary artery and r8 = 0.49 for the left one. Diameters of the aorta and the pulmonary trunk indicated the relative increase in the values. A different tendency was observed for the internal diameters of the arterial duct and both pulmonary arteries, which were relatively decreased with increased foetal age. The largest diameter was observed in the arterial duct, the intermediate--in the right pulmonary artery and the smallest--in the left pulmonary artery. The cross-sectional area of the descending aorta was equal to the sums of the sectional areas of the aortic isthmus and the arterial duct (r9 = 0.97). The cross-sectional area of the pulmonary trunk was equal to the sums of the sectional areas of the both pulmonary arteries and the arterial duct (r10 = 0.91).